Obesity is defined as a chronic disease associated with abnormal and excessive fat accumulation (World Health Organization (WHO) 2018). Obesity is commonly measured using body mass index (BMI), a calculation that divides an adult's weight in kilograms by their height in metres squared. A BMI above 35 kg/m2 is classified as obese, and morbid obesity as a BMI above 40 kg/m2 (National Institute for Health and Care Excellence (NICE), 2014). However, weight and BMI are not always an accurate measure of obesity, since BMI does not distinguish between muscle, body fat and its distribution (Hanson and Barber, 2019). Waist circumference measures the accumulation of central body fat and is also considered a good measure of obesity (Ashwell and Gibson, 2009). South Asian people are at a higher risk of centralised body fat with lower waist circumference and of developing diabetes (Rush et al, 2004). Waist circumferences vary across different ethnicities and therefore no universal measurement can be applied worldwide (Qiao and Nyamdorj, 2010). Therefore, to correctly identify patients at risk of health problems practice nurses should use both BMI and waist circumference assessment tools (Table 1).
Table 1. Risk classification using BMI and waist circumference
| Waist circumference | ||||
|---|---|---|---|---|
| Low | High | Very High | ||
| Male | <94cm | 94-102cm | >102cm | |
| Female | <80cm | 80 - 88cm | > 88cm | |
| BMI 18.5-24.9 Normal | No increased risk | No increased risk | Increased risk | |
| BMI 25-29.9 Overweight | No increased risk | Increased risk | High risk | |
| BMI 30-34.9 Obese I | Increased risk | High risk | Very high risk | |
| BMI >35-39.9 Obese II | High risk | Very high risk | Very high risk | |
| BM1>40 Obese III (Morbid) | Very high risk | Extremely high risk | Extremely high risk | |
| BMI ≥50 Super obese | Extremely high risk | Extremely high risk | Extremely high risk | |
Table 2. Common complications associated with surgical procedures
| Surgical Procedure | Potential Complications |
|---|---|
| Gastric band | Slippage, recurrent chest infections, band erosion, too tight a band, reflux, oesophageal dysmotility, leaking band, infected port |
| Sleeve gastrectomy | Oesophageal dysmotility, reflux, stricture, staple line leak, ulcers, gastritis, less commonly dumping syndrome |
| Roux-en-Y gastric bypass | Dumping syndrome, bowel obstruction, staple line leak, internal hernia, kidney stones, nutritional deficiencies |
Obesity is steadily rising, with 64% of adults in England in 2017 classified overweight or obese (NHS Digital National Statistics, 2019). Obesity is strongly linked to diseases such as cardiovascular disease, type 2 diabetes mellitus (T2DM), non-alcoholic fatty liver disease (NAFLD), polycystic ovary syndrome (PCOS), obstructive sleep apnoea, musculoskeletal and respiratory disorders, cancer, as well as psychological illness (WHO, 2018). Obese people are seven times more likely to develop T2DM compared to people of a healthy weight (Abdullah et al, 2010), and Black, Asian and other minority ethnic groups are also at greater risk of T2DM at a lower BMI. Therefore, NICE (2014) recommends Black, Asian and other minority ethnic patients are identified as high risk at a BMI 27kg/m2 or above.
Factors affecting weight gain
Many factors are attributed to weight gain such as: excessive food intake; sedentary lifestyle; sleep patterns; socio-economic deprivation; medications such as steroids and insulin; depression; genetics; and endocrine disorders (Whitehead and Bano, 2019). Hormonal imbalances including ghrelin, leptin, gut hormones, androgens and oestrogens can also increase obesity, altering fat distribution and metabolism. Ghrelin levels increase before eating a meal which leads to hunger, these levels reduce after eating leading to satiety (feeling satisfied). Women with PCOS have low levels of ghrelin, which do not increase after eating; therefore these women remain hungry, increasing food consumption, resulting in weight gain (Whitehead and Bano, 2019). Ongoing research suggests weight gain may also be associated with dysfunction of gut microbiota resulting from a diet high in poor quality carbohydrates. Including probiotics, such as live yoghurt, and prebiotic foods such as peas, lentils, garlic, onions, vegetables, nuts and grains, may improve the gut flora function and assist in weight loss (Ferrarese et al, 2018). Current research in this area includes faecal transplantation to improve the gut microbiome to treat obesity and associated metabolic diseases (Marotz and Zarrinpar, 2016).
Management of obesity
Weight loss can improve these aforementioned diseases. The NHS in England recommends that weight loss should be supported in the community with lifestyle interventions. NICE (2019) has developed interactive flow charts to assist in supporting obese patients. Those who meet the NICE (2014) criteria should be offered a referral by general practice to a specialist weight management service (Tier 3):
- BMI of 40 kg/m2 or more
- BMI between 35kg/m2 and 40kg/m2 with other medical conditions such as diabetes, hypertension, high cholesterol and obstructive sleep apnoea.
Within Tier 3, patients are assessed and supported by nurses, dietitians, endocrinologists and psychology services using conservative measures including medication such as orlistat (Xenical) and antidiabetic medication including liraglutide (Saxenda) or exenatide (Bydureon) to assist in weight loss and improvement of co-morbidities (Whitehead and Bano, 2019). If these patients engage with Tier 3 services, and wish to be considered for surgery, they are referred to the surgical multidisciplinary Team (MDT) (Tier 4).
The MDT discusses each patient individually in consideration for a surgical intervention (bariatric surgery). Surgical interventions can improve the comorbidities in severely obese people (Gloy et al, 2013; Chang et al, 2014). However, bariatric surgery alone is unlikely to achieve weight loss or improve comorbidities; patients must modify their eating behaviours, emotions and increase their activity (Radcliffe, 2018). Consequently, nurses, dietitians, psychologists and exercise therapists are required to support patients and their families both before and after surgery. However, NICE (2014) recommends patients are discharged back to primary care 2 years after surgery. Practice nurses are therefore pivotal in caring for and supporting bariatric surgery patients in primary care and it is imperative that practice nurses are aware of the initial referral criteria, surgical interventions, complications, nutritional requirements and long-term follow-up requirements.
Surgical interventions
Surgical interventions have become more widely accessible in England (NICE, 2014) during the last 10 years, with evidence of long-term sustained weight loss and improvement of obesity related conditions such as diabetes and hypertension (British Obesity and Metabolic Surgery Society (BOMSS), 2018). Although, currently bariatric surgery is not available to patients in Wales and Northern Ireland. As the rates of bariatric surgery continue to rise, practice nurses need to understand the implications of each bariatric surgical procedure and to possess the knowledge and skills to promote safe and effective individualised patient-centred care (Nursing and Midwifery Council (NMC), 2018).
Common bariatric surgical procedures
Several surgical procedures are commonly used to assist in weight loss and the improvement of comorbidities, which are mainly performed laparoscopically. Other procedures such as bilio pancreatic diversion/duodenal switch (BPD/DS) and one-anastomosis gastric bypass have been less commonly performed in the UK and are not discussed in this article.
Adjustable gastric band surgery
Ten years ago the insertion of an adjustable gastric band was the most common bariatric surgical procedure performed in England. An inflatable gastric band is placed around the top portion of the stomach, creating a small pouch. The vagus nerve is stimulated by food passing through the band increasing feelings of satiety after eating. Saline is injected into the band to adjust the cuff around the stomach, optimising the feelings of satiety. This operation is commonly undertaken as a day case with few initial complications. On the whole, if patients eat a healthy diet nutritional deficiencies are rare, although excessive or persistent vomiting can also lead to potential nutritional deficiencies and slippage of the gastric band. Within England currently only 10% of bariatric surgical procedures are adjustable gastric bands (BOMSS, 2018).
Complications of adjustable gastric band surgery
Long-term complications such as intolerance, slippage, band erosions, port site infections and reflux are reported which require the band to be removed.
Patients may present with signs and symptoms (Table 3) such as difficulty swallowing, vomiting, reflux, recurrent chest infections and night coughs, commonly associated with a tight or slipped gastric band. Deflation of the band is required, but this must be undertaken using the correct equipment and techniques and requires referral to the local bariatric surgical team. If these symptoms are severe or continue after deflation of the gastric balloon, a slipped gastric band should be considered. Radiology or an oesophago-gastro-duodenoscopy (OGD) can identify a slipped gastric band. If confirmed the gastric band will be removed as an emergency procedure under general anaesthetic. The recognition and management of signs and symptoms is crucial for patients following bariatric surgery.
Table 3. Potential post-operative symptoms, cause and recommended action
| Signs and symptoms | Potential cause/problem | Action |
|---|---|---|
| Total dysphagia: difficulty swallowing saliva, vomiting (gastric band) | Acute band slippage (herniation) – Emergency assessment even if patient is well | Urgent referral for band deflation and potential surgery |
| Gastrointestinal bleed: vomiting blood, pain, tachycardia, hypotension | Anastomotic bleed, potential ulcer | Urgent referral to surgical team/ED or band deflation, OGD, CT scan |
| Epigastric pain: nausea, vomiting | Gall stones, ulcer, reflux | Prescribe or increase PPI, discuss diet, exclude gall stones, USS and referral to surgeon, severe vomiting refer to ED |
| Intestinal obstruction: vomiting, pain | Anastomotic stricture, internal hernia or port site hernia | Urgent referral to surgical team/ED, CT scan |
| Chest pain, tachycardia, breathlessness | Pulmonary embolus, myocardial infarction, gastric pouch problems, anastomotic leak | CT scan, urgent referral to surgical team/ED |
| Abdominal pain | Potential obstruction from internal hernia, anastomotic leak, constipation, biliary colic | Referral to surgical team/ED, CT scan, OGD, USS |
| Reflux, regurgitation, vomiting, no dysphagia of fluids | Band slip, gastrojejunal stenosis, oesophageal dysmotility, hiatus hernia | Refer to bariatric surgical team, OGD and/or barium swallow |
| Port site infection (gastric band) | Gastric band erosion, infected band, leaking band | Refer to bariatric surgical team |
| Constipation | Pre-operative liver shrinking diet Post-operative diet (Both diets lack fibre) | Increase fluids, Include laxatives, linseed, vegetables, exercise depending on pre/post-op stage |
| Diarrhoea | Dumping syndrome | Reduce carbohydrate and fat in diet. Increase protein and vegetables |
| Hair Loss/thinning | Lack of protein, selenium, zinc | 60-80 g protein (reduced if renal failure). Good quality multivitamin |
ED, emergency department; OGD, oesophago-gastro-duodenoscopy; CT, computerised tomography; PPI, proton pump inhibitor; USS, ultrasound scan
Source: Adapted from BOMSS Emergency Department Management of Bariatric Patients, 2014bOesophageal dysmotility is associated with signs and symptoms of reflux, regurgitation and vomiting, and can be identified using barium swallow. To assist practice nurses in supporting patients safely and effectively, Table 3 lists common signs and symptoms, potential causes/problems and the recommended action required. Depending on the severity of the symptoms, patients should be referred to the local bariatric surgical team for review or advised to attend the emergency department.
Sleeve gastrectomy
Sleeve gastrectomy (also called gastric sleeve) procedures account for approximately 36% of bariatric surgical procedures performed in England (BOMSS, 2018). In this procedure, approximately 80% of the stomach is removed reducing food intake to approximately 80–100 ml. Therefore, lifelong nutritional and mineral supplements are required to prevent any deficiencies. Additionally, removal of the fundus of the stomach also removes the hormone ghrelin, which suppresses appetite and hunger. Patients with diabetes see significant reduction in their diabetic medications immediately after surgery (Shah et al, 2018). However, the monitoring of diabetes and associated comorbidities should continue for life.
Gastric bypass (Roux-en-Y)
There are several different types of gastric bypass operations being performed in the England such as the mini bypass (one anastomosis gastric bypass) but the Roux-en-Y Gastric bypass remains the most common (45% of bariatric procedures in England) and has established long-term data and evidence base (National Bariatric Surgery Registry, 2018). The Roux-en-Y bypass creates a smaller stomach (25-30 ml) and re-routes the passage of gastric contents, bypassing the stomach and proximal small bowel thus altering the digestion and absorption of food and medication from the gut. Consequently, nutritional supplementation is required for life following this procedure, to prevent deficiencies such as thiamine, iron and vitamin B12. Additionally, the absorption of medications can also be affected and therefore medications with a narrow therapeutic index such as lithium, phenytoin and digoxin should be closely monitored (Geraldo et al, 2014). Patients with diabetes see significant reduction in their blood glucose levels. They will require review and adjustment of diabetic medications immediately after surgery and should be reviewed regularly (Shah et al, 2018). Additionally, hypertension also improves quickly, primarily due to the rapid weight loss (Yska et al, 2013). Therefore, the practice nurse should regularly monitor the patient's blood glucose levels and blood pressure following a gastric bypass.
Complications of gastric bypass (Roux-en-Y) and sleeve gastrectomy
Complications following a gastric bypass and sleeve gastrectomy are more common in the initial stages (3–4 weeks); Table 2 outlines common complications associated with each procedure. The practice nurse must be aware that patients reporting symptoms (Table 3) of nausea, vomiting, and abdominal pain following a gastric bypass or sleeve gastrectomy require urgent referral to the bariatric surgical team for assessment and investigation. This is to exclude complications such as staple line leak, an internal hernia (gastric bypass), bowel obstruction, reflux, aspiration and strictures. Long-term complications such as ulcers, strictures and reflux can also occur. Patients may present with poor eating patterns, difficulty swallowing, regurgitation or reflux, which may be associated with complications or oesophageal dysmotility, hiatus hernia or over-eating (Whitehead and Bano, 2019). Patients presenting to the practice nurse with long-term complications should be referred to the local bariatric team for further advice, investigation and management.
Furthermore, eating sugar or highly refined carbohydrates or fats can result in ‘dumping syndrome’. Dumping syndrome is a collection of symptoms such as abdominal cramping, bloating, nausea, vomiting and diarrhoea. Some patients also experience hypoglycaemia due to increased levels of insulin resulting in tachycardia, palpitations, anxiety and sweating. These symptoms occur more frequently after a gastric bypass, but have been less commonly reported following a sleeve gastrectomy. Dumping syndrome can occur at any stage following surgery. The practice nurse can improve symptoms by advising these patients to reduce fats and simple carbohydrates in their diet, in exchange for protein, high fibre and complex carbohydrates. Patient should be encouraged to regularly keep a food diary, eating more regular small meals, while monitoring and recording blood glucose levels (Mechanick et al, 2013). If the patient's symptoms do not improve, they should be referred to the local bariatric team for further investigation, management and support.
As previously mentioned, gastric bypass and sleeve gastrectomy surgery affect the absorption of some oral medications due to the reduction in gastric acid production. For example the bioavailability of metformin increases by 50% after a gastric bypass surgery (Busetto et al, 2017). Therefore, slow/modified release preparations are not recommended; oral solutions or rapid-release preparations are preferred. Therefore, alternative preparations may need to be considered and a medication review with the practice nurse/doctor is recommended. Multivitamin and minerals as well as calcium and vitamin D supplementation are recommended for both the gastric bypass and sleeve gastrectomy procedures due to the risk of micronutrient deficiencies from reduced food intake and potential malabsorption.
Nutritional status monitoring and multivitamin requirements and blood tests
Patients must be monitored for nutritional requirements following bariatric surgery by reviewing their dietary intake, compliance with multivitamin supplements and regular bloods tests. Surgery can result in nutrient deficiencies due to decreased food intake, food intolerances and malabsorption. Fundamentally, patients need to be encouraged to eat a healthy balanced diet, focusing on eating protein and vegetables. It is recommended that bariatric surgery patients eat approximately 60g of protein intake per day (Faria, 2011), but this level should be reduced if the patient has impaired renal function. The practice nurse can support the patient in maintaining and improving good eating behaviours by reiterating the importance of drinking plenty of fluids, eating slowly and taking time to taste and enjoy foods (Hanson et al, 2018), and being aware of portion sizes. Graham et al (2019) suggests practice nurses are well positioned to provide support to the patient and family in coping using a biopsychosocial approach.
Multivitamin supplements should be prescribed following local prescribing guidance. Currently, Forceval once daily is recommended for malabsorptive procedures such as a gastric bypass. However, patients following a sleeve gastrectomy are also at risk due to the restricted stomach capacity and potential reduction in intrinsic factor. Patients should be advised to purchase a good quality over-the-counter complete multivitamin and mineral supplement, taken twice daily, such as Sanatogen A-Z Complete, Superdrug A-Z multivitamins and minerals, Tesco A-Z Complete multivitamins and minerals, Lloyds pharmacy A-Z or Holland and Barrett ABC Plus. Table 4 indicates the nutritional supplements recommended by BOMSS (2014a) dependent on the bariatric procedure and the individual patient. Table 5 indicates the blood tests required according to procedure.
Table 4. Nutritional supplements recommended following bariatric surgery
| Nutritional supplement | Gastric bypass | Sleeve gastrectomy | Gastric band |
|---|---|---|---|
| Can affect the absorption of iron, vitamin B12, calcium and vitamin D | Can affect the absorption of iron, vitamin B12 | If too tight a gastric band this may affect quality of diet: protein and iron | |
| Multivitamin | Yes | Yes | Yes |
| Iron | Yes | Yes | Yes |
| Folate 5 mg | Yes | Yes | Yes |
| Vitamin B12 | Yes | Yes | Multivitamin |
| Calcium & vitamin D | Yes | Yes | Multivitamin |
| Selenium | Included in the multivitamin | Included in the multivitamin | Multivitamin |
| Zinc and copper | Included in the multivitamin | Included in the multivitamin | Multivitamin |
Table 5. Annual blood tests following bariatric surgery
| Blood test | FBCU&ELFT | Ferritin | Folate | Vit B12 | Calcium | Vit D | Vit A | Vit E&K | ZincCopper | Selenium |
|---|---|---|---|---|---|---|---|---|---|---|
| Gastric band | Y | Y | Y | Y | Y | Y | N | * | N | N |
| Sleeve gastrectomy | Y | Y | Y | Y | Y | Y | N | * | * | * |
| Gastric bypass | Y | Y | Y | Y | Y | Y | * | * | Y | * |
Vit, vitamin; FBC, full blood count; U&E, urea and electrolytes; LFT, liver function tests
* Possibly measure where there are concerns of deficiency or unexplained fatigue, hair loss, chronic diarrhoea. For night blindness measure vitamin A If prolonged vomiting measure thiamine If neuropathy or unexplained anaemia are identified measure vitamin E and K Source: Adapted from BOMSS 2014aPregnancy following bariatric surgery
To ensure good maternal nutrition and safe development of the foetus, women are advised to delay pregnancy for 12-18 months following bariatric surgery (Mechanick et al, 2013). Unintended pregnancy can occur for several reasons: the effects of weight loss on improvement in menstrual patterns (Teitelman et al, 2006); increased fertility; and satisfaction with changes to body image and sexuality (Saber et al, 2008). Additionally, oral contraceptive medication may be ineffective following gastric bypass or a sleeve gastrectomy due to the reduction of acid in the stomach (Schlatter, 2017) and postoperative vomiting and/diarrhoea, which are common after surgery as patients learn to live with altered physiology and eating behaviours. Therefore, practice nurses can counsel women pre-operatively and recommend alternative contraceptive methods such as an intrauterine device (IUD) (Graham et al, 2014; Hillman et al, 2011). IUDs are highly efficacious, with a good safety profile; however IUDs can be difficult to insert in obese women, other alterative contraception methods can be obtained from United Kingdom Medical Eligibility for Contraception (2016). If pregnancy occurs within 12–18 months following bariatric surgery patients should commence a pregnancy multivitamin such as Pregnacare, Seven Seas Pregnancy and Centrum Pregnancy Care with additional folic acid and be referred to the specialist bariatric team if nutritional deficiencies or complications are suspected or advice required (BOMSS, 2014a).
Psychological changes after surgery
Patients who have had a sleeve gastrectomy and gastric bypass surgery tend to lose weight rapidly. Most weight loss occurs within the first 6 months, and continues over the next 6–12 months. While some patients enjoy this transition, others struggle with their new body image. Difficulties can occur for many reasons (Kitzinger et al, 2012). Some patients struggle to comprehend their new image unable to see and embrace their transforming body and continue with body dysmorphia. Other patients struggle with accepting positive comments about their changing body image; this can also cause problems in their long-term relationships (Radcliffe, 2018) and requires patients, with the help of health practitioners, to manage many of these psychological issues, which includes revisiting the patient's original pre-surgery goals. According to Monte et al (2018), after sleeve gastrectomy depression and anxiety symptoms were seen to improve in the majority of patients, with one-third of cases having antidepressant and antianxiety medication regimens altered by dose decrease or discontinuation. However, Cunningham et al's (2012) study of patients taking antidepressants following a gastric bypass showed little reduction in these medications post-surgery. Therefore, practice nurses should review antidepressants and antianxiety medications. Additionally, the practice nurse should listen to the patient's concerns; involve family/friends, if permitted by the patient, and counsel within the nurse's limitations. Sign posting the patient to specialist support groups such as British Obesity Surgery Patients Association (BoSPA), which provides information for people considering obesity surgery and supports patients on their journey post-operatively, or referral to specialist psychologists or counsellors where appropriate.
Excess skin and weight regain
Rapid weight loss can result in excess skin, and exercise can improve the skin's elasticity (Coen and Goodpaster, 2016). However, when it is over-stretched the skin will not return to normal. Excess skin can become infected, excoriated and chaffed from friction. This can be very problematic for patients both physically and pyschologically, which may be difficult to manage. The practice nurse is in a position to assess skin folds for persistent skin conditions such as intertriginous dermatitis, panniculitis, cellulitis and skin ulcerations. Intertrigo dermatitis is commonly associated with small red bumps or spots on both sides of the skin folds. The rash can feel itchy or prickly with a burning pain. These skin folds, when not infected, are best managed with good hygiene: keeping them clean, and drying by patting or use of a cool hair dryer. Application of tea tree oil can reduce itching; barrier cream can help if skin is inflamed. Placing a soft cotton cloth or using supportive under garments can reduce friction between large skin folds. Infected or ulcerated skin folds do not commonly affect both skin folds and can be caused by fungus, bacteria or yeast; management requires treating the cause with the appropriate medication. Large amounts of excess skin can also impede physical activity (Baillot et al, 2013). Further surgery may be possible (British Association of Plastic Reconstructive and Aesthetic Surgeons, 2017), but this is dependent on local Clinical Commissioning Group criteria and referral to a plastic body contouring surgeon. Patients should be advised that plastic surgery is not always funded in order that expectations are managed and the practice nurse may need to compassionately and sensitively support patients.
Weight regain can occur for many reasons: hormonal changes; emotional eating due to life events; tiredness and stresses. Additionally, some patients start eating frequent small meals all day, experience loss of control in eating, and form poor eating habits. Therefore, patients need support to develop a balanced and realistic view in understanding why they are regaining weight. The practice nurse can assist in supporting the patient with developing strategies to regain control such as focusing on patients' portion control; recommending smaller plate and bowls; taking photographs of portion sizes; encouraging mindful eating behaviours such as eating slowly, chewing well and enjoying the flavour of foods; and managing old habits by adapting new behaviours, activities and self-discipline (Radcliffe, 2018). Some patients will require referral to a specialist dietitian or psychologist.
Conclusion
Practice nurses are essential in guiding and supporting obese patients. Furthermore, the practice nurse has a pivotal and unique position to review the patient's comorbidities such as diabetes, blood pressure and medications. Nurses have the skills to support and refer patients who experience excess skin, weight regain, physiological and body image problems. Therefore, it is imperative for practice nurses to understand the referral process, common bariatric procedures, complications, nutrition and supplementation and the requirement for annual blood investigations. The ability to recognise signs and symptoms of associated complications including nutritional deficiencies is vital in providing safe advice and effective care. Referring to the local bariatric surgical team for expert advice is essential in providing timely effective care.
KEY POINTS
- Obesity is steadily rising, with 64% of adults in England in 2017 being classified as overweight or obese
- As obesity associated with many health complications, every opportunity should be taken to support patients to lose weight and maintain weight loss
- Bariatric surgery in England is relatively new, with its usage having increased dramatically in the last 10 years. Practice nurses require knowledge of bariatric surgery to undertake their role effectively
- it is imperative for practice nurses to understand the referral process, common bariatric procedures, complications, nutrition and supplementation and the requirement for annual blood investigations